Two women in a doctor's office. The woman on the left is sitting on a stool and is wearing a black top and jeans. She has long dark hair and is looking off to the side with a serious expression on her face.

PCOS Is Now Called PMOS: What You Need to Know

July 21, 2026

A condition affecting approximately 10%-13% of women worldwide recently got a major update.

The disorder formerly known as polycystic ovary syndrome (PCOS) is now known as polyendocrine metabolic ovarian syndrome (PMOS). The name change is intended to better reflect the wide range of health effects this condition can have on people of reproductive age.

"It's important to know that PMOS is very common," says Rogerio Lobo, MD, an expert in reproductive endocrinology at Columbia. "But the diagnosis is often missed, so I think the more information that a woman has about the possibility of having PMOS, the better."

Dr. Lobo explains what PMOS is, why the name has changed, and what signs to watch for.

What is PMOS?

PMOS (formerly known as PCOS) is the most common reproductive endocrine disorder in women. It is diagnosed when people experience at least two of three different types of symptoms:

Irregular menstruation: People with PCOS often have irregular or absent periods.
Hormonal imbalance: Elevated levels of male-type hormones, such as testosterone, cause symptoms like increased body hair or skin problems.
Polycystic ovaries: Ovaries become enlarged and surrounded by small cysts, which are visible on an ultrasound.

Not all symptoms are required to make a diagnosis, and many people experience different combinations of symptoms, resulting in different types of the disorder. These variables can make PMOS difficult to diagnose. Further, some people experience subtle symptoms, making it underdiagnosed.

How does PMOS differ from PCOS?

The former designation of PCOS called the disorder "polycystic," which overemphasized the role of the ovary and fell short of describing the overall patient experience, namely the metabolism aspect. An international consortium of experts was formed to come up with treatment guidelines for PCOS, and the group moved to rename the disorder to better reflect its metabolic effects.

The hallmark of the emphasis on metabolism is insulin resistance, which most women with PCOS or PMOS have. Insulin resistance must be followed over one's life to prevent conditions like diabetes, hypertension, or cardiovascular disease. By using "polyendocrine" and "metabolic," the new name reflects the reality that different disorders and organ systems may be involved.

Even though the disorder has been renamed, it has not changed—whether you call it PMOS or PCOS makes no difference. "I'm still going to treat the patient the same way based on her specific symptoms and experience," says Dr. Lobo.

What causes PMOS?

We don't know what causes PMOS, but it probably has a genetic basis. However, no specific gene abnormality has been identified, and while it is more common in some families, the mode of inheritance is not known.

We know from studies of genetic variations in DNA that there are various "susceptibility factors," or a few chromosomes that might lead to PMOS. So, if you have a genetic susceptibility factor, you're more likely to have PMOS. Symptoms may be subtle, but they can increase in response to several possible triggers, with weight gain being among the most common.

A woman with a very subtle genetic variation could have a very healthy life with no expression of symptoms at all.

When should someone ask their health care provider about PMOS?

These are the main signs women should watch for if they are wondering whether they have PMOS:

Irregular menstrual cycles
Extra male-type hormones, such as testosterone, which could cause increased body hair or acne that doesn't respond to normal treatment; often, routine blood tests cannot detect an elevation in these hormones, so monitoring symptoms is important.
Weight gain or the inability to lose weight; although weight gain is not a criterion for PMOS, someone experiencing multiple PMOS symptoms may also have trouble losing weight due to insulin resistance.
A slightly enlarged multicystic ovary on ultrasound; although the new name de-emphasizes the ovary, this finding might provide a clue as to the possible diagnosis.

What treatments are available for people with PMOS?

We've come a long way in the treatment of PMOS, but there isn't one therapy for the disorder because women present with different symptoms.

Common treatments include interventions to regulate the menstrual cycle, such as progesterone or birth control pills, and to stimulate ovulation for patients who have trouble getting pregnant.

With any treatment, we also recommend lifestyle management, like diet and exercise, as a good preventive strategy for both PMOS symptoms and lifelong health.

What do you want everyone to know about PMOS?

"The condition can be very subtle and mild, so you shouldn't be afraid of a PMOS diagnosis," says Dr. Lobo. "It's very easy to treat based on the specific symptoms a person is experiencing." But people should be aware of the possibility that they could have PMOS, he adds, and reach out to their health care provider with any questions.

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Rogerio Lobo, MD, is a professor of obstetrics and gynecology in the Division of Reproductive Endocrinology & Infertility at Columbia University Vagelos College of Physicians and Surgeons.